Just in case anyone is looking at switching to a newer version of PHP on your website, I offer the following.

I have been running PHP version 7.2 on my site for a few days now and have not had any problems. Prior to this I ran version 7.0 for almost 18 months and then 7.1 for the last three months. The last release of PHP 5x was 5.6, which is no longer actively supported, but it will still receive critical security updates as needed for another year. As you probably know, there was no version 6.